title: Association between warfarin use and incidence of ischemic stroke in Japanese hemodialysis patients with chronic sustained atrial fibrillation: a prospective cohort study.
abstract: BACKGROUND
  Although generally recommended for atrial fibrillation (AF) in the general population, the efficacy and safety of warfarin in hemodialysis patients remains controversial. Warfarin use in hemodialysis patients may confer an additional risk of bleeding that is not appreciated in patients without renal failure because hemodialysis patients have platelet defects and receive anticoagulation agents during dialysis. The incidence of major bleeding was reported to be higher in Japanese AF patients on warfarin therapy compared to patients in other countries, suggesting that racial differences may influence bleeding tendency. Thus, examining risks and benefits of warfarin therapy in Japanese hemodialysis patients with AF is important.
  
  
  METHODS
  In order to determine associations between warfarin use and new ischemic stroke events, major bleeding, and all-cause mortality, a prospective cohort study of 60 Japanese hemodialysis patients with chronic sustained AF was conducted using Cox proportional modeling and propensity score matching.
  
  
  RESULTS
  The mean patient age was 68.1 years. During 110 person-years of follow-up, 13 ischemic strokes occurred. After adjusting for CHADS2 score, warfarin use was not associated with a significant reduction in ischemic stroke events [hazard ratio (HR) 3.36; 95 % confidence interval (CI) 0.94-11.23]. Similar results were obtained after propensity score matching (HR 3.36; 95 % CI 0.67-16.66). Warfarin use was not associated with significant increases in major bleeding or all-cause mortality.
  
  
  CONCLUSIONS
  These results suggest that warfarin may not prevent ischemic stroke in Japanese hemodialysis patients with chronic sustained AF. Adequately powered studies are needed to determine the risks and benefits of anticoagulation therapy in these patients.
authors.affiliation: Center for Inter-organ Communication Research, Niigata University Graduate School of Medical and Dental Sciences, Asahimachi 1-757, Chuo-ku, Niigata, 951-8510, Japan, minakowa@med.niigata-u.ac.jp.
authors.forename: Minako
authors.initials: M
authors.lastname: Wakasugi
authors.forename: Junichiro James
authors.initials: JJ
authors.lastname: Kazama
authors.forename: Akihide
authors.initials: A
authors.lastname: Tokumoto
authors.forename: Kensuke
authors.initials: K
authors.lastname: Suzuki
authors.forename: Shinji
authors.initials: S
authors.lastname: Kageyama
authors.forename: Kaoru
authors.initials: K
authors.lastname: Ohya
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Miura
authors.forename: Mamoru
authors.initials: M
authors.lastname: Kawachi
authors.forename: Takuma
authors.initials: T
authors.lastname: Takata
authors.forename: Masaaki
authors.initials: M
authors.lastname: Nagai
authors.forename: Minoru
authors.initials: M
authors.lastname: Ohya
authors.forename: Keiko
authors.initials: K
authors.lastname: Kutsuwada
authors.forename: Hideo
authors.initials: H
authors.lastname: Okajima
authors.forename: Isei
authors.initials: I
authors.lastname: Ei
authors.forename: Sachio
authors.initials: S
authors.lastname: Takahashi
authors.forename: Ichiei
authors.initials: I
authors.lastname: Narita
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use*; D044466:Asian People; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000188:drug therapy* / Q000208:ethnology / Q000401:mortality; D002545:Brain Ischemia / Q000175:diagnosis / Q000208:ethnology / Q000401:mortality / Q000517:prevention & control*; D002908:Chronic Disease; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000208:ethnology / Q000401:mortality / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D057216:Propensity Score; D016016:Proportional Hazards Models; D011446:Prospective Studies; D006435:Renal Dialysis / Q000009:adverse effects / Q000401:mortality; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis / Q000208:ethnology / Q000401:mortality / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome; D014859:Warfarin / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D014859:Warfarin